Children are coming to school "frightened" after playing violent computer games, a headteacher has warned.

In the monthly newsletter to parents of children at Whitstable Junior School in Kent, Gill Moody voiced her concerns over some of the children playing "inappropriate computer games".

It is the second time she has written to parents asking them to consider the impact playing games containing 18-rated material could be having on their children.

She said: "We are becoming increasingly aware that some of our children are playing inappropriate computer games and as a result are coming to school frightened by what they are seeing.

"Please do consider the impact 18-rated material has on young children who do not understand the content and cannot cope with the feelings or images they are seeing.

"No apologies for repeating this item in this newsletter from the last newsletter.

"I appreciate that this is only a very small minority of children, but if your child is playing Grand Theft Auto and you have not checked out what this game includes - please do so."

In February, the headteacher of Coed-y-Brain Primary School, in Llanbradach, Caerphilly, sent a letter to parents following concerns that children as young as six were re-enacting scenes from Grand Theft Auto, which sees players take on the role of criminals in America's dark and seedy underworld.

Morian Morgan said young pupils were initiating games involving "simulating rape and sexual intercourse" as well as having playground chats about "drug use".

A letter sent to parents said children were "acting out scenes from the game which include the strongest of sexual swear words", "having conversations" about sexual acts and "play acting extremely violent games that sometimes result in actual injury".

He stressed that the letter was a way of making parents aware of the trend, rather than criticising them.